So I have an inspection of the car tomorrow for ITV (MOT) in Spain and I want to fix the washer wiper not working.

It pushes out the headlight mechanism ok, pumps all sound ok and reservoir is full. But nothing coming out at windscreen or headlights. Someone I see mentioned compressed air to maybe get the tubes unblocked. Any idea how I can do that? Any DIY options or can only a garage like do this?

Bit of a last minute request but any help much appreciated as don't want it to fail the inspection on something stupid. Especially since I know about it.